Event processing is a computer-based method of tracking and analyzing streams of data and information about things happening in the real world, known as “events”, and deriving a conclusion from the events. An event can occur in a business context, such as a financial transaction or a sales figure, in an industrial process, such as a temperature rising above a threshold, or an event can be some occurrence in a computer. Complex event processing is event processing that combines data from multiple data sources to infer events or patterns suggesting more complicated circumstances.
Event processing services process events based on a set of rules, which typically include a condition rule statement and an action rule statement. Patterns are detected based on the condition rule statement and an output is generated and transmitted based on the action rule statement. For example, a simple condition rule statement might look for a specific value appearing in information from a data source and a simple action rule statement might generate a report that the value was found. In complex event processing, the condition rule statements and action rule statements are reported by multiple clients and each client generates data and information related to the rule statements, all of which must be processed and analyzed to identify patterns and perform actions.